Why does Firefox 38+ silently abort web requests over 20 secs?
I'm experiencing the exact same problem described here: https://support.mozilla.org/en-US/questions/1047223?fpa=1 https://bugzilla.mozilla.org/show_bug.cgi?id=1135282
I've tested Firefox 38.4 (ESR), and 42.0 (current release at time of writing).
To summarise, when hitting a website that takes a long time (> 20 secs or so) to send its response, Firefox will silently abort the request. That is, the progress spinner in the top left stops, no Timeout error page is displayed, and whatever was displayed in the Firefox content window at the time of the request will remain there. To check the behavior, navigate to: http://www.jeffersonscher.com/res/sleep120.php
Other tested browsers (Edge 13, IE11, Chrome 47, Firefox ESR 31) will wait 120 seconds, then render the text "Slept 120 seconds before generating HTML".
I've toyed with a variety of about:config network timeout settings to try and overcome the issue, with no luck. Hopefully a contributor will be able to repro using the provided link.
If you're registered and can repro the above, please +1 so the defect isn't closed like it was last time :)
Additional System Details
- User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/47.0.2526.73 Safari/537.36
I forgot to mention- Firefox's silent abort time varies with each request. I've had the waiting spinner stop anywhere from 20 to 100 seconds into the request.
Boot the computer in Windows Safe Mode with network support (press F8 on the boot screen) to see if that helps.
Create a new profile as a test to check if your current profile is causing the problem.
See "Creating a profile":
If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems.
Boot the computer in Windows Safe Mode with network support (press F8 on the boot screen) to see if that helps. Create a new profile as a test to check if your current profile is causing the problem.
Not sure if you are level 1 helpdesk or an answer-bot cor-el, but neither of these two suggestions will fix my issue.
1. Safe mode won't make a difference- the issue doesn't appear on multiple other browsers or Firefox 31 ESR on my computer when booted normally.
2. Profiles aren't the issue as I've tested Firefox installations on 3 different machines ranging from fresh install to upgraded installs (on 3 different Firefox versions).
Did you fail to reproduce the issue with a current version of Firefox cor-el? If so, what version of Firefox worked for you?
Is there a way to re-open the bug that I linked to in my original question? Hopefully some fresh dev eyes may result in a repro.
I was unable to replicate the problem from my home computer. Until now I have been testing from behind a corporate proxy (I didn't think it was relevant- maybe I should have mentioned that).
My best guess is that there is some difference between the networking layer in Firefox 31 and Firefox 38-42 (and other browsers tested- Edge, Chrome), that results in its connections getting prematurely munched by the proxy. Or perhaps an about:config proxy timeout. I'll have a look.
I'll also try installing WireShark and see if I can get some more detail. If anyone has a clue to a relatively recent change in Firefox's networking that may cause this issue, I'd be happy to hear it!